As a background art in this technical field, for example, there are Japanese Patent Application Laid-Open Publication No. 2013-138171 and Ryoji Kosugi et. al., Development of SiC super-junction (SJ) device by deep trench-filling epitaxial growth, Materials Science Forum Vols. 740-742 (2013) pp 785-788.
Japanese Patent Application Laid-Open Publication No. 2013-138171 describes a semiconductor device in which an n-type charge amount and a p-type charge amount in an n-type column region and a p-type column region constituting a super-junction structure are equalized in a cell region, and a charge balance change region in which the n-type charge amount in the super-junction structure is gradually made larger than the p-type charge amount as going toward an outer circumferential direction of the cell region is provided in a peripheral region.
In addition, Ryoji Kosugi et. al., Development of SiC super-junction (SJ) device by deep trench-filling epitaxial growth, Materials Science Forum Vols. 740-742 (2013) pp 785-788 reports an example in which a trench having a width of 2.7 μm and a depth of 7 μm formed in a 4H—SiC substrate is backfilled with an SiC layer without generating a void on the premise of the manufacture of the super-junction structure.